Potential role of the gymnosperm microbiome in a changing climate

植物微生物群，即定植于植物内外组织的微生物，已被证明对植物的生长发育有很大影响。这些微生物代表了生命的三个领域：真核生物，特别是真菌、细菌和古生菌，简称古生菌。虽然土壤和植物组织外的定植微生物已被深入研究，但仅属于细菌和真菌的植物组织内定植微生物的特性及其对植物生长和发育的影响已被表征，包括许多裸子植物。然而，关于古生代成员的研究报告很少。最近，利用基因鉴定和生物信息学，有诱人的证据表明，古生菌的一些成员不仅在植物内部组织中定居，而且通过生长素的生物合成、增加营养供应和保护免受非生物(特别是氧化和渗透)胁迫而与植物相互作用。关于植物和古生物，也有一定程度的植物专一性的证据。古生菌的功能特征揭示了与真菌相互作用的遗传能力，以及在碳氮循环中扮演重要角色：例如，固定二氧化碳和氮气。这些事实揭示了古生代在大多数植物和树木中的一个重要但未被观察到的作用。由于气候变化已经通过北半球更温暖和更干燥的夏季表现出来，裸子植物微生物群的潜在改善作用可能对裸子植物在不断变化的环境条件下的生长和生存非常重要。利用分子和培养相结合的技术，我建议：(I)继续评估植物外部和内部组织定植细菌在裸子植物生长和发育中的作用；(Ii)利用分子技术提供第一个证据，证明外部和/或内部植物组织定植古生菌在裸子植物生长和发育中的发生和潜在功能；(Iii)尝试第一个从任何植物中分离和培养定植古生菌的外部和/或内部植物组织；以及(Iv)评估外部和内部植物定植细菌、真菌和古生菌(如果有)在预计气候变暖的紧张环境条件下对裸子植物生长和发育的交互影响。这些压力条件将包括高温、干旱和营养缺乏，研究是在受控环境下进行的。这项工作将首次对裸子植物的发生及其在裸子植物生长发育中的作用进行评估。此外，这项工作可能导致获得第一个从任何植物的外部和/或内部组织中分离到的古生菌菌株(S)，并评价在胁迫条件下细菌、真菌和古生菌对裸子植物生长的交互影响。

The plant microbiome, i.e., microorganisms that colonize internal and external plant tissues, has been shown to be very influential on plant growth and development. These microorganisms represent all three domains of life, the Eukarya, particularly the fungi, the Bacteria and the Archaeabacteria, or Archaea for short. While soil and external plant tissue colonizing microbes have been studied intensively, internal plant tissue colonizing microbes belongingj only to the bacteria and fungi have been characterized with respect to their identity and effects on plant growth and development, including many gymnosperm species. However, very little work has been reported on members of the Archaea. Recently, using gene identification and bioinformatics, there is tantalizing evidence to suggest that some members of the Archaea not only colonize internal plant tissues, but also interact with plants by auxin biosynthesis, increasing nutrient supply, and protection against abiotic (especially oxidative and osmotic) stress. There is also some evidence for a degree of plant specificity regarding plants and Archaea. Functional signatures of Archaea reveal the genetic capacity for the interplay with fungi as well as playing an important role in the carbon and nitrogen cycle: e.g., CO2 and N2 fixation. These facts reveal an important, yet unobserved role for the Archaea in most plants and trees. With climate change already manifesting through warmer and drier summers in the northern hemisphere, the potential ameliorating effects of the gymnosperm microbiome may be very important for gymnosperm growth and survival under changing environmental conditions. Using a combination of molecular and culture-based techniques, I propose to (i) continue evaluating the role of external and internal plant tissue colonizing bacteria in gymnosperm growth and development; (ii) provide the first evidence of the occurrence and potential function of external and/or internal plant tissue colonizing Archaea in gymnosperm growth and development using molecular techniques; (iii) attempt to be the first to isolate and culture external and/or internal plant tissue colonizing Archaea from any plant; and (iv) evaluate the interactive effects of external and internal plant colonizing bacteria, fungi and Archaea (if available) on growth and development of gymnosperms under stressful environmental conditions that are anticipated to occur with a warming climate. These stressful conditions will include elevated temperatures, drought and nutrient deprivation, with studies performed under controlled environments. This work will be the first to evaluate the occurrence and role of the Archaea in gymnosperm growth and development. In addition, this work may result in obtaining the first Archaea strain(s) ever to be isolated from external and/or internal tissues of any plant species and to evaluate the interactive effects of bacteria, fungi and Archaea on gymnosperm growth under stressful conditions.